There are various techniques for adding acoustic effects to a sound which is output from a speaker. For example, a frequency response is applied to an input audio signal as an acoustic effect. When an audio signal to which a frequency response is applied is supplied to a speaker, the sound to which the frequency response is applied is output from the speaker. As a result, by changing the frequency response which is applied, it is possible to variously change the characteristics of the sound. An equalizer device for providing such acoustic effects is disclosed in, for example, Japanese Laid Open Patent Publication No. 2010-50875.